The Global Dispersion Model GDM52 describes global fundamental-mode Love and Rayleigh wave dispersion in the period range 25 to 250 seconds. The Rayleigh wave part of the model includes azimuthal anisotropy. The model was derived from a large number of observed dispersion curves, collected from globally distributed seismographic stations and earthquakes in the years 2000-2009.
The model is published in Geophysical Journal International:
Ekstrom, G., A global model of Love and Rayleigh surface wave dispersion and anisotropy, 25-250 s, Geophy. J. Int., doi:10.1111/j.1365-246X.2011.05225.x
This research was made possible by support from the National Science Foundation, most recently by NSF grant EAR-0838093.